Hints

Use these only after trying the exercises.

MATH-C03-C-001

Read the row index first, then the column index.

Column 2 is the second vertical list.

For matrix multiplication, the middle dimensions must match. The output keeps the outside dimensions.

Check whether the middle dimensions match.

The first output entry uses the first row of the matrix.

One product entry comes from one row and one column.

Transpose swaps rows and columns.

A diagonal matrix scales coordinates separately.

For $Wx$ , the output length is the number of rows of $W$ .

Use the phrase "row dot product."

Check the middle dimensions first. Then keep the outside dimensions.

The batch size stays on the outside. The output-feature count comes from the last dimension of the weight matrix.